The present invention concerns the use for augmenting or enhancing the aroma or taste of smoking tobacco, smoking tobacco flavors and smoking tobacco articles as well as substitute smoking tobacco, substitute smoking tobacco flavors and substitute smoking tobacco articles of cis and/or trans isomers of 5-isopropyl-3-nonene-2,8-dione as well as optical isomers thereof wherein such cis and trans isomers of 5-isopropyl-3-nonene-2,8-dione have the structures: ##STR1## respectively.
There is a continuing search for smoking tobacco flavor compositions which can vary, fortify, modify, enhance, augment or otherwise improve the flavor and/or aroma of smoking tobaccos, substitute smoking tobaccos, smoking tobacco articles, substitute smoking tobacco articles, smoking tobacco flavors and substitute smoking tobacco flavors. A limited amount of such materials that give rise to these properties is available from natural sources but the natural materials obtainable therefrom are subject to wide variations in quality, are expensive and are often in critically short supply. More specifically, there is a considerable need for substituents having solanone-like hay-like and bready notes and burley tobacco-like aromas and cocoa-like nuances prior to smoking and which, on smoking, supply burley and cocoa notes as well as mouthfeel, body and natural tobacco taste and smoke impact to smoking tobaccos, smoking tobacco articles and smoking tobacco flavors as well as to substitute smoking tobaccos, substitute smoking tobacco articles and substitute tobacco flavors.
Shigematsu et al. in Agr. Biol. Chem., Vol. 35, No. 11, pages 1751-1758, 1971 (Title: Studies on Composition of Tobacco Smoke Part XVI, Volatile Compounds from the Neutral Fraction of Tobacco Smoke Condensates (2)) disclose the presence of 5-isopropyl-3-nonene-2,8-dione as a constituent of tobacco smoke. Shigematsu et al, however, do not disclose the organoleptic properties of said 5-isopropyl-3-nonene-2,8-dione or its use as a flavorant and as a flavor enhancer in conjunction with smoking tobacco and smoking tobacco articles.
Johnson and Nicholson in J. Org. Chem. 30, page 2918 (1965) disclose the synthesis of 5-isopropyl-3-nonene-2,8-dione (racemic mixtures of D- and L-isomers of the trans isomer of 5-isopropyl-3-nonene-2,8-dione having the structures: ##STR2## The Johnson and Nicholson syntheses encompass the following reaction schemes: ##STR3## in addition, Demole, U.S. Pat. No. 3,992,458, issued on Nov. 16, 1976 discloses the synthesis of cis and trans isomers of 5-isopropyl-3-nonene-2,8-dione according to the following reaction scheme: ##STR4## This mixture, however, is indicated to be useful only as a precursor for the production of solanone.
Nothing in the prior art discloses the unexpected, unobvious and advantageous usefulness of cis and/or trans isomers of 5-isopropyl-3-nonene-2,8-dione or stereoisomers thereof as flavorants and as flavor enhancers in conjunction with smoking tobacco and smoking tobacco articles.